Rather than use a microwave, this same recipe may be implemented with a double boiler. Place the morsels in top of double boiler over hot (though not boiling) water. Do not cover. When the majority of morsels are shiny, stir until just melted. Ensure that water doesn't come into contact with the melted sauce. Remove from heat, blend in peanut butter, and transfer into a large bowl. Add chow mein noodles and marshmallows, then proceed as described above.